2 hours ago, IanSolo_FFG said:maybe you could impose that difficulty level on yourself by playing thematic open groups rather than optimal open groups.
This is what I do. e.g. I won't bring Royal Guards to most missions as it doesn't seem thematic for them to be there.
I also try to let the initial and reserved groups dictate the open groups I bring. No merc groups? Then I probably won't bring any (although I may still bring Tuskens to a desert map or a wampa to a snow map for thematic reasons). A bunch of stormies? I'll bring more stormies of different types.
This doesn't always work (esp. with low threat level), but it's fun to try.